package listeners;

import android.graphics.Matrix;
import android.graphics.PointF;
import android.util.FloatMath;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.ImageView;

public class ImageOnTouchListener implements OnTouchListener {
	
	// These matrices will be used to move and zoom image
	Matrix matrix = new Matrix();
	Matrix savedMatrix = new Matrix();

	// We can be in one of these 3 states
	static final int NONE = 0;
	static final int DRAG = 1;
	static final int ZOOM = 2;
	int mode = NONE;

	// Remember some things for zooming
	PointF start = new PointF();
	PointF mid = new PointF();
	float oldDist = 1f;
	String savedItemClicked;
	

	@Override
	public boolean onTouch(View v, MotionEvent event) {
		 // TODO Auto-generated method stub

	    ImageView view = (ImageView) v;
	    dumpEvent(event);

	    // Handle touch events here...
	    switch (event.getAction() & MotionEvent.ACTION_MASK) {
	    case MotionEvent.ACTION_DOWN:
	        savedMatrix.set(matrix);
	        start.set(event.getX(), event.getY());
	        mode = DRAG;
	        break;
	    case MotionEvent.ACTION_POINTER_DOWN:
	        oldDist = spacing(event);
	        if (oldDist > 10f) {
	            savedMatrix.set(matrix);
	            midPoint(mid, event);
	            mode = ZOOM;
	        }
	        break;
	    case MotionEvent.ACTION_UP:
	    case MotionEvent.ACTION_POINTER_UP:
	        mode = NONE;
	        break;
	    case MotionEvent.ACTION_MOVE:
	        if (mode == DRAG) {
	            // ...
	            matrix.set(savedMatrix);
	            matrix.postTranslate(event.getX() - start.x, event.getY()
	                    - start.y);
	        } else if (mode == ZOOM) {
	            float newDist = spacing(event);
	            if (newDist > 10f) {
	                matrix.set(savedMatrix);
	                float scale = newDist / oldDist;
	                matrix.postScale(scale, scale, mid.x, mid.y);
	            }
	        }
	        break;
	    }

	    view.setImageMatrix(matrix);
	    return true;
	}

	private void dumpEvent(MotionEvent event) {
	    String names[] = { "DOWN", "UP", "MOVE", "CANCEL", "OUTSIDE",
	            "POINTER_DOWN", "POINTER_UP", "7?", "8?", "9?" };
	    StringBuilder sb = new StringBuilder();
	    int action = event.getAction();
	    int actionCode = action & MotionEvent.ACTION_MASK;
	    sb.append("event ACTION_").append(names[actionCode]);
	    if (actionCode == MotionEvent.ACTION_POINTER_DOWN
	            || actionCode == MotionEvent.ACTION_POINTER_UP) {
	        sb.append("(pid ").append(
	                action >> MotionEvent.ACTION_POINTER_ID_SHIFT);
	        sb.append(")");
	    }
	    sb.append("[");
	    for (int i = 0; i < event.getPointerCount(); i++) {
	        sb.append("#").append(i);
	        sb.append("(pid ").append(event.getPointerId(i));
	        sb.append(")=").append((int) event.getX(i));
	        sb.append(",").append((int) event.getY(i));
	        if (i + 1 < event.getPointerCount())
	            sb.append(";");
	    }
	    sb.append("]");
	}

	/** Determine the space between the first two fingers */
	private float spacing(MotionEvent event) {
	    float x = event.getX(0) - event.getX(1);
	    float y = event.getY(0) - event.getY(1);
	    return FloatMath.sqrt(x * x + y * y);
	}

	/** Calculate the mid point of the first two fingers */
	private void midPoint(PointF point, MotionEvent event) {
	    float x = event.getX(0) + event.getX(1);
	    float y = event.getY(0) + event.getY(1);
	    point.set(x / 2, y / 2);
	}

}
